Spring Boot @RestController vs @RequestMapping Explained

Understanding Request Mapping in Spring Boot While working on my Spring Boot projects, I explored how request mapping plays a crucial role in handling client requests efficiently. 🔹 @RequestMapping This is a general-purpose annotation used to map HTTP requests to handler methods. It can be applied at both class and method level and supports multiple HTTP methods. 🔹 @GetMapping Specifically designed for handling HTTP GET requests. It makes the code more readable and is commonly used for fetching data from the server. 🔹 @PostMapping Used for handling HTTP POST requests. Ideal when sending data from client to server, such as form submissions or creating new records. Why use specific mappings? Using @GetMapping, @PostMapping, etc., improves code clarity and makes APIs more expressive compared to using @RequestMapping for everything. In real projects, choosing the right mapping annotation helps in building clean and maintainable REST APIs. #SpringBoot #Java #BackendDevelopment #RESTAPI #CodingJourney #LearningInPublic

🚀 Developed a basic REST API using Spring Boot to handle HTTP requests and responses. 🔹 What I implemented: Created a REST Controller using @RestController Used @RequestMapping to define base URL (/api) Built a GET API using @GetMapping("/student") 🔹 API Endpoint: http://localhost:8080/api/student 🔹 Output: "Student data" 🔹 Key Learnings: How Spring Boot handles HTTP requests Understanding request → controller → response flow Basics of REST API development Excited to move next into POST APIs and sending real data using @RequestBody 🔥 #SpringBoot #Java #BackendDevelopment #LearningJourney #CSE 

🧬 Spring Boot – Understanding @RequestBody Today I learned how Spring Boot handles data coming from the client using @RequestBody. 🧠 Key Concept: 👉 "@RequestBody" is used to receive JSON data from the frontend and convert it into a Java object automatically. 🔁 Flow: Client (JSON) → @RequestBody → Java Object 💡 This makes API development clean and efficient without manual parsing. ✔️ Helps in handling POST & PUT requests ✔️ Automatically maps request data to objects ✔️ Simplifies backend code 📌 Real Use Case: • Creating users • Updating data • Handling form submissions 💻 DSA Practice: • Prime number check • Factorial calculation 🧠 Quick Check: "@RequestBody" is used to receive data from client ✅ ✨ Understanding how data flows from frontend to backend is a key step in mastering REST APIs. #SpringBoot #Java #BackendDevelopment #RESTAPI #WebDevelopment #DSA #LearningInPublic

Last week our Spring Boot service froze completely under load. No errors. No exceptions. Just requests piling up and users  seeing blank screens. Turns out it was thread pool exhaustion — one of the most  common production issues that looks nothing like what it is. I wrote a detailed breakdown of: → How we diagnosed it using thread dumps and Actuator metrics → Why adding timeouts was the immediate fix → How we properly solved it with async thread pool isolation → What to check in your own Spring Boot service right now Full article link in the comments 👇 If you are building Java microservices — this one is worth  bookmarking. #Java #SpringBoot #Backend #Microservices #SoftwareEngineering  #Programming #BackendDevelopment #TechBlog

🧠 After learning Request Scope, I explored something even more practical today 👀 **Session Scope in Spring Boot** 🌐 Here’s the simple idea 👇 ✅ One bean instance is created per **user session** ✅ The same object is reused across multiple requests from the same user ✅ Different users get different objects This makes it useful for 👇 🔹 user login data 🔹 shopping cart 🔹 session-based preferences 🔹 multi-step workflows 💡 Quick difference: Request Scope → new object every request Session Scope → same object for the same user 💡 My takeaway: Session scope helps maintain **user-specific state across multiple requests** without recreating objects again and again ⚡ #Java #SpringBoot #SessionScope #BackendDevelopment #LearningInPublic

Why write 100 lines of code when the same can be done in 10? 🚀 Day 1 of my Spring Learning Series Today, I started my journey into the Spring Framework, aiming to understand how modern enterprise applications are built efficiently. The first concept I explored was the difference between: • **Languages (Java)** → the foundation we build on   • **Technologies (Servlets)** → tools that help solve specific problems   • **Frameworks (Spring)** → structured solutions that handle most of the heavy lifting  A simple way to see it: Building with a language is like starting from raw materials, while using a framework is like working with a ready-made structure — you focus more on customization than construction. This shift in perspective made me realize how powerful frameworks are in writing cleaner, scalable, and maintainable code. Looking forward to diving deeper into Spring in the coming days. What was the first framework that changed the way you code? #SpringFramework #Java #BackendDevelopment #SoftwareEngineering #LearningInPublic #TechJourney

Day 11 — #100DaysOfJava ☕ No new topic today. Only revision — and honestly, it felt more valuable than learning something new. Java Basics ---------------------- ->JVM runs your code. JDK is the full toolkit to write and run Java. JRE is just for running. ->Variables store data — int, double, String, boolean. ->Scanner reads user input from keyboard. I went back through Day 1–9 and here’s my journey in short: • Basics: JVM, JDK, JRE, variables, Scanner • Strings & Arrays: Immutable strings, StringBuilder, fixed-size arrays • OOP: Overloading, overriding, this, super, constructors • Advanced OOP: Abstract classes, inner/anonymous classes, boxing • Interfaces & Lambda: Functional interfaces, lambda, enum • Exceptions & Threads: try-catch, throw/throws, start vs run • Collections: List, Set, Map, Iterator basics • Modern Java: Optional, record, var, sealed classes • Tools: Maven (pom.xml), AWS EC2 basics Big realization: Concepts that confused me earlier now make sense — revision is powerful. Most people rush ahead. Slowing down helped me more. What’s your revision strategy? -What is your revision strategy? -Drop it in the comments . would love to learn from you! Day 1 ....................... 10 ✅ #100DaysOfJava #Java #JavaDeveloper #LearningInPublic #100DaysOfCode #BackendDevelopment #Revision #CodeEveryDay #JavaBeginners #LearnJava

🚀 Week 1 Progress Report Focused on building strong fundamentals across multiple areas: 💡 DSA: Arrays, Recursion, started Dynamic Programming 💻 Full Stack: Started React, Spring Boot CRUD APIs completed ☕ Java: Strengthening core concepts ⚙️ System Design: Basics + URL Shortener project 🧠 Aptitude: Clock & Calendar, Time & Work 🗄️ DBMS: SQL (DDL, DML), CRUD operations, Joins 📈 Consistency > intensity. Building step by step. #DSA #FullStack #Java #SpringBoot #React #SQL #SystemDesign #LearningJourney

Learning and implementing REST APIs with Spring Boot What's happening here: @RestController :- marks this class as a REST API handler @RequestMapping("/employee") :- base URL for all endpoints @Autowired :- injects the Service layer dependency GET /display :- a simple test endpoint to verify the API is live POST /save :- accepts Employee data as JSON and saves to DB GET /getAll :- fetches all employee records from the database Implementing Dependency Injection and a structured Layered Architecture has highlighted the importance of writing clean, maintainable code. #REST #API #BackendDevelopment #SpringBoot #Java

A simple .java file triggers a full system: 👉 Compile → Bytecode (.class) 👉 Load → Classes into memory 👉 Link → Verify, prepare, resolve 👉 Initialize → Static data execution 👉 Execute → Interpreter + JIT Behind the scenes 🧠 • Heap → Stores objects • Stack → Handles method calls • Method Area → Class metadata • GC → Automatically cleans memory ⚡ The real power? JVM decides: • When to optimize code (JIT) • How memory is managed • How performance scales That’s why Java isn’t just a language — it’s a runtime ecosystem. 💡 My takeaway: If you understand JVM, you stop writing “just code” and start building efficient systems. Right now, I’m focusing on: Backend + System Design + Cloud ☁️ If you’re learning the same, let’s connect 🤝 #Java #JVM #Backend #SystemDesign #Programming #LearnInPublic #DeepakKumar